1. Field of the Invention
The present invention relates to a three-dimensional (3D) interconnection structure and a method of manufacturing the same, and more particularly, to a 3D interconnection structure for interconnection of chips or packages three-dimensionally stacked using a wafer or interconnection between upper and lower surfaces of a wafer and a method of manufacturing the 3D interconnection structure.
2. Discussion of Related Art
With the remarkable development of information technology (IT), market demand for products in which several functions converge in one terminal is increasing, and a great deal of research for three-dimensionally stacking multifunctional chips or packages is under way. FIG. 1 illustrates an example of a 3D stacked package employing conventional wire bonding. Referring to FIG. 1, wire bonding is used for connection between chips and also between a chip and a package. However, wire bonding deteriorates performance and increases a package size.
Another conventional 3D interconnection method employs through-silicon via (TSV) technology in which via hole is formed in a silicon wafer and then plated. Since TSV technology enables micro-processing, it is frequently used for electronic chips that involve many inputs and outputs, and thin wafers are frequently used for it. However, it is difficult to transfer signals at a high speed, and significant signal loss occurs. To solve these problems, that is, to enable high-speed signal transmission and minimize signal loss, research on polymer-shield (PS)-TSV technology in which the core of via is insulated by low-loss dielectric is under way. However, it is difficult to perform a PS-TSV process, and the process cost is high.
In yet another 3D interconnection method, a V-shaped through hole is formed by wet-etching a silicon wafer, and then an electrode is deposited to connect the upper and lower surfaces of the wafer. In this case, the width of the through hole on one side is too small to form a plurality of electrodes or to transfer signals at a high speed. Also, it is difficult to perform a photoresist process due to the through hole.
FIG. 2 is a perspective view of an example of a bidirectional optical transceiver sub-module. In this structure, a transmitter and receiver are both mounted on the upper surface of a platform, and significant electrical or optical crosstalk occurs. Such a conventional bidirectional optical communication module having a transmitter and receiver generally employs two packages for the transmitter and receiver and a metal housing for connecting the two packages to minimize electrical or optical crosstalk between the transmitter and receiver. This process is complicated and expensive. Also, even when the transmitter and receiver are disposed on one plane of one platform, the above-mentioned electrical or optical crosstalk still occurs.